1. Field of the Invention
The present invention relates to therapeutic gas delivery systems and, more particularly, to a mask that forms a seal with a patient's face during gas delivery.
2. Description of the Related Art
One class of respiratory face mask assemblies can be of two different types: a single limb circuit type and a dual limb circuit type. For a single limb circuit, the face mask assembly typically includes a valve and an exhaust port, and, for a dual limb circuit, the face mask assembly typically does not include a valve but provides a valveless conduit instead. Other types of masks may also be useful for different applications. Thus, hospitals and other health care facilities typically stock several different types of face mask assemblies that are used for different applications. Cost and storage space considerations associated with stocking several different face mask assemblies can be significant.